From the Characteristics of Ḥaddādīs

Shaikh Rabī ibn Hādī Al-Madkhalī, may Allāh protect him, said:

So one in whom are found these characteristics is a Ḥaddādī–one who rises against the scholars, defames them, and wants to bring about their downfall in the way I have mentioned is a Ḥaddādī.
They used to lie, defame, and defame, so we brought out the lies of their shaikh into plain view, his mistakes, and his misguidance, after which they [only] increased in excessive zealotry toward him.
So everyone who resembles these [people], falling into excesses of zealotry toward individuals, rejecting evidences and clear proofs, and defaming people of the Sunnah, then [he] is a Ḥaddādī and worse then the Ḥaddādīs.

Source: [extract]

Title mine (Trans.)
Translated by Mikail ibn Mahboob Ariff